#THE PROPOSED BOREHOLE DRILLING

[jobskenyaplace]

THE PROPOSED BOREHOLE DRILLING, EQUIPPING, WATER TOWER INSTALLATION, ELEVATION OF 1 No. 20M3 DOUBLE LAYERED PLASTIC TANK AND CONSTRUCTION OF 2 No. WATER COLLECTION POINTS AT KEGOGI MARKET SITUATED IN KITUTU CHACHE NORTH CONSTITUENCY, KISII COUNTY

LAKE BASIN DEVELOPMENT AUTHORITY TENDER AUGUST 2024  INVITATION TO TENDER TENDER NO. LBDA/OT – 01/2024-2025; THE PROPOSED BOREHOLE DRILLING, EQUIPPING, WATER TOWER INSTALLATION, ELEVATION OF 1 No. 20M3 DOUBLE LAYERED PLASTIC TANK AND CONSTRUCTION OF 2 No. WATER COLLECTION POINTS AT KEGOGI MARKET SITUATED IN KITUTU CHACHE NORTH CONSTITUENCY, KISII COUNTY 1. The LAKE BASIN DEVELOPMENT AUTHORITY…

[spacetimewithstuartgary]

Laboring at Big Bend Tunnel

New Jersey looms large in the history of Labor Day. Two labor organizers with roots in the state—Peter J. McGuire and Matthew Maguire—are often credited with being the first to propose the concept of a Labor Day holiday in the United States.

John Henry, legendary for his work on the railroads, was a nineteen-year-old who came from New Jersey as well, at least according to some historians. Many details of the folk hero’s life remain subject to historical dispute, but the ‘steel-driving’ freedman is widely lionized in ballads as a man who did battle with a steam-powered rock drill and won.

Steel drivers were laborers tasked with hammering dynamite holes into rock during the construction of railroad lines in the 1800s. As the legend goes, Henry—a freedman working on a tunnel on the Chesapeake and Ohio (C&O) Railway in West Virginia—was so strong and skilled that he set out to prove to the railroad companies that he could drill faster than a steam-powered drill, a new tool that threatened the jobs of steel-drivers at the time.

“Using two 10-pound hammers, one in each hand, he pounded the drill so fast and so hard that he drilled a 14-foot hole into the rock,” according to an account of the contest published by the National Park Service. “The legend says that the drill was only able to drill nine feet. John Henry beat the steam drill and later died of exhaustion.”

There isn’t consensus on where the reputed contest took place, but one of the leading candidates is Big Bend Tunnel (also called Great Bend Tunnel) in West Virginia. The 6,450-foot (1,966-meter) tunnel cuts off an eight-mile bend in the Greenbrier River, which winds around Big Bend Mountain before joining the New River to the west. The tunnel, built by over 800 men, many freed slaves and Irish immigrants, was the longest on the C&O line when it was completed in 1872.

On August 23, 2024, the OLI (Operational Land Imager) on Landsat 8 captured this image of the area where the tunnel bores through red shale in Big Bend Mountain. Cleared forest along the track is visible on either side of the tunnel’s east and west boreholes. The town of Talcott, home to the John Henry Historical Park and an eight-foot-tall bronze statue of John Henry, is visible to the east of the tunnel.

Despite the historical park and research that points to Big Bend Tunnel as the location of Henry’s feat, some scholars believe that Lewis Tunnel, 45 miles to the east in Virginia, is a more likely setting for the duel. Others think that it may have happened in the Coosa and Oak Tunnels in Alabama.

Whatever the location, the legacy of John Henry lives on in songs performed by Arthur Bell, Harry Belafonte, Bruce Springsteen, Gabriel Brown, Johnny Cash, Van Morrison, and many other musicians.

Few who have studied the legend believe Henry actually died of exhaustion during the contest. Others have suggested he died in a rock slide, from fever, or from the lung disease silicosis. Either way, his story has become a potent symbol of the sweat and sacrifice that American workers have given to build the United States into what it is today.

NASA Earth Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Photo by Dave Bieri, courtesy of the National Park Service. Story by Adam Voiland.

[geosightca]

What is the importance of borehole deviation in underground mining?

Borehole deviation is a critical factor in underground mining. This indicates an unintended deviation of the borehole from the planned route. Understanding and managing borehole deviation is essential to mine success. Let's consider why this is important.

Accuracy of Resource Mining

Accuracy is critical in mining. Borehole deviation can cause targets to be missed. This means that valuable resources remain unused. By monitoring hole deviations, miners ensure that they are hitting their intended targets. This maximizes resource utilization and increases efficiency.

Safety considerations

Safety is paramount in underground mining. Deviation from borehole can create hazardous conditions. It may intersect with other boreholes or underground structures. This increases the risk of falls and accidents. Correctly managing the deviation of the mine hole increases the safety of the miners.

Impact on costs

Mining is expensive. Detoured boreholes mean wasted labor and materials. Correcting a deviant open road increases costs. By minimizing borehole deviation, mining companies save on drilling costs and reduce overall costs.

Longevity of equipment

Drilling equipment is expensive. Stray drill holes can cause excessive wear on equipment. This leads to higher maintenance costs and shorter equipment life. Borehole deviation monitoring helps keep equipment in good condition and saves money in the long run.

Environmental impacts

Environmental responsibility is crucial in modern mining. Borehole deviation can cause unnecessary environmental disturbances. According to the proposed routes, mining minimizes its ecological footprint. This helps to protect the surrounding environment.

Data Accuracy

Accurate data is very important for efficient mining. Borehole deviation can distort the data collected by the borehole. This affects decision making and planning. Ensuring the smallest deviation preserves the integrity of the geological data.

Conclusion

Borehole deviation is an important part of underground mining. This affects accuracy, safety, cost, equipment life, environmental impact and data accuracy. Borehole deviation management ensures efficient and safe mining operations. For a mining company, it is imperative to focus on minimizing borehole deviation to be successful.

[helmerichpayne]

IMPROVED BHA SAG CORRECTION AND UNCERTAINTY EVALUATION BRINGS VALUE TO WELLBORE PLACEMENT

Recent well positioning uncertainties evaluation per SPE published ISCWSA model for MWD survey tools suggests that 80% of the inclination measurement error budget is a consequence of BHA sag. BHA sag is the misalignment of the directional sensor with the borehole direction due to deflection of the MWD drill collar under gravity and borehole curvature. The magnitude of the error depends on BHA type and geometry, sensor spacing, hole size and several other factors.

This paper presents a new methodology based on modern 3D BHA/Hole interacting modeling for BHA sag corrections and residual error evaluation at each MWD survey stations. 11 different typical 17½" and 12¼" rotary and steerable motor BHA’s with variable gauge stabilizers were computed in multiple configurations (borehole geometry, BHA settings, friction...) following a Monte Carlo process which involved more then a million simulations. Results of this study show that the residual BHA sag uncertainty as proposed by the ISCWSA model can be further reduced by as much as 50%.

A simplified software automated process was developed in order that Operations Support Centers can easily integrate the proposed methodology as part of near real time Survey Management advanced processing routines. The proposed process contributes to improve significantly wellbore placement through the pay zone while drilling. Reduced trajectory positional uncertainties contribute to the construction of sound geological models for rational well target design, positioning and development pattern fine tuning during the drilling campaign.

In turn reservoir management including mature fields shall benefit from improved Wellbore Placement as a multidisciplinary task by locating more accurately layer tops and contacts. Read out the full tech paper from here: https://www.helmerichpayne.com/resources/technical-publications/improved-bha-sag-correction-and-uncertainty-evaluation-brings-value-to-wellbore-placement. Download the tech paper PDF from here: https://www.helmerichpayne.com/media/technical-publications/Improved-BHA-Sag-Correction-and-Uncertainty-Evaluation-Brings-Value-to-Wellbore-Placement.pdf. Reach out to us to know more: https://www.helmerichpayne.com/contact.

We are a drilling rig company in oil and gas sector. We provide automated drilling solutions along with safety, contact us to know more!

[neetemp]

Technical and Financial Template for Water Wells

Steps for digging an artesian water well and extracting & after extracting water

Digging an artesian water well and extracting water requires specialized knowledge and equipment, so it is important to consult with a professional well driller before attempting this process. However, here are the general steps involved in the process:

Site selection: The first step is to choose a suitable location for the well. An artesian well requires a natural underground aquifer or water-bearing formation that is under pressure. A qualified well driller will typically use geological surveys and other tools to locate a suitable site.

Drilling: Once the site has been chosen, the well driller will drill a borehole deep into the ground until the aquifer is reached. The well may be lined with casing to prevent the borehole from collapsing and to keep the water clean.

Installation of well screen: A well screen is typically installed at the bottom of the borehole to prevent sediment and debris from entering the well.

Development: After the well has been drilled, it must be developed to remove any debris or sediment that may have entered the borehole during drilling. This is typically done by pumping large amounts of water down the well and backwashing it to remove any debris.

Installation of pump and piping: Once the well has been developed, a pump and piping system will be installed to extract the water from the well. The type of pump and piping system used will depend on the specific needs of the well.

Testing: After the pump and piping system have been installed, the well will be tested to ensure that it is producing water at the desired rate and that the water quality meets the necessary standards.

Maintenance: Regular maintenance of the well is necessary to ensure that it continues to function properly and provide a reliable source of water. This may include periodic testing of the water quality, replacing worn or damaged parts, and cleaning the well

Storage: The first step after extracting water from an artesian well and desalination is to store the water in a suitable storage tank or reservoir. This may be necessary if the water is not needed immediately or if the demand for water varies throughout the day.

Treatment: Depending on the intended use of the water, further treatment may be necessary to remove any remaining impurities or contaminants. This could include filtration, disinfection, or additional chemical treatment.

Distribution: Once the water has been treated and stored, it can be distributed to its intended destination. This may involve a network of pipes or a system of pumps to move the water to where it is needed.

Monitoring: It is important to regularly monitor the quality of the water to ensure that it meets the necessary standards and remains safe for its intended use. This may involve regular testing and analysis of the water.

Maintenance: Regular maintenance of the system is also important to ensure that it continues to function properly and provide a reliable source of water. This may include repairing or replacing equipment, cleaning filters or membranes, and inspecting the system for any signs of damage or wear.

A feasibility study is an analysis of the viability of a proposed project, in this case, the construction of a water well. The study assesses the technical, financial, and economic feasibility of the project, and helps to determine whether the project is viable or not.

Here are some of the key factors that would need to be considered in a feasibility study for a water well:

Water Availability: The first and most important factor is the availability of water in the proposed location. A hydrogeological survey would need to be conducted to assess the quantity and quality of water available in the area.

Water Quality: The quality of water must meet the required standards for domestic or agricultural use. Water samples should be analyzed to determine if it is safe for human consumption and irrigation.

Location: The location of the well must be suitable for construction and maintenance. Factors such as accessibility, topography, and proximity to potential sources of contamination must be considered.

Construction Costs: The cost of constructing the well, including drilling, casing, and pumping equipment, must be estimated. The cost of any necessary permits and licenses must also be included.

Operating Costs: The ongoing costs of operating and maintaining the well, including electricity, maintenance, and repair costs, must be estimated.

Revenue Potential: The potential revenue from the well, such as selling water to nearby communities or agricultural operations, must be estimated.

Return on Investment: A financial analysis must be conducted to determine the expected return on investment. This should consider the costs of construction and operation, as well as the potential revenue generated by the well.

Based on these factors, a feasibility study can be conducted to determine whether the construction of a water well is viable or not. It is important to note that the study should be conducted by qualified professionals with experience in hydrogeology and well drilling to ensure accurate results.

[seachranaidhe]

Fracking: Tamboran in new licence bid in Fermanagh

In 2014, Tamboran faced opposition to its plans to drill a gas exploration borehole at a quarry in Belcoo

  An energy company has restarted the process which could lead to fracking for natural gas in Fermanagh.

Tamboran Resources (UK) has applied for a licence to evaluate the natural gas in the shale and sandstone rocks in the south west of the county.

The company said any decision about…

[turretteam30-blog]

Soil Testing Services for Construction Projects

Whether you are building your dream home, making an extension to your existing home or having a commercial property, there's one thing which is of utmost importance, plate testing. There are a number of engineering consultancy firms that offer a number of soil testing services for commercial, industrial and residential projects that include geotechnical testing, soil testing and analysis. It is essential that you employ a consultancy that has the necessary and expertise so that accurate geotechnical data can be gathered for designing the proposed structure's foundation and footings.

Collecting the Data- How's the geotechnical data gathered? Well, this is accomplished by certified geotechnical engineers and soil experts by using mechanical and manual boring tools. Next, a specified number of boreholes are drilled by these engineers at pre determined depths to ensure that soil samples may be collected for further analysis. The analytical process is really as per the accepted industry and international standards. Based on the analysis, a website investigation report is ready containing your geotechnical data combined with necessary recommendations. Ascertaining Land Quality- The soil testing services provided by a well reputed engineering consultancy may help in determining the general quality of the land. Inside the construction industry this calls for field testing of soil and rocks. Normally, the tests include plate bearing tests and in site density testing, necessary for getting accurate geotechnical information. Soil and rock testing involves tests for ascertaining the efficacy of point load, frost heave, direct shear strength, magnesium sulphate, etc. Likewise, one has to determine the slake durability index along at the same also ascertain the prevailing density and water content levels. Similarly, further tests have to be conducted for analyzing the density and particle size, soil suction and moisture content. Tests using the BRE and TRI methods are conducted to ascertain the necessary data. Ascertaining Soil Suitability- Soil testing services are necessary for determining the suitability and the overall soil quality of a building project. Conducting the necessary tests will throw up important geotechnical data that will assist in determining whether the soil characteristics and quality would work for the structure or not. It is very important to possess this data beforehand because it helps in taking informed decisions and also enable you to plan strategically. Further, the data produced by these tests will inform whether the soil suitability matches the industry and national standards. Bushfire Protection- Engineers, planners and consultants inside the construction industry are required to provide a professional report for almost any construction activity inside the bushfire prone areas. The main aim of the bushfire report is to protect lives and properties from any bushfire threats. A comprehensive report works well for developing a sound strategy to limit damages to lives and properties. Finally, soil testing services are a vital prerequisite when obtaining a building construction license.

[ultralivingsoil-blog]

Soil Moisture Sensors Made Simple

Whether or not you're building your dream residence, making an extension to your present dwelling or creating a industrial property, there's one thing that is of utmost importance, soil testing. There are a number of engineering consultancy corporations that provide a variety of soil testing providers for industrial, Wikipedia Here industrial and residential projects that include geotechnical testing, soil testing and evaluation. It's important that you simply hire a consultancy that has the necessary and expertise so that accurate geotechnical knowledge could be gathered for designing the proposed structure's foundation and footings.

How is the geotechnical information gathered? Effectively, that is performed by certified geotechnical engineers and soil experts by using mechanical and manual boring tools. Subsequent, a specified number of boreholes are drilled by these engineers at pre decided depths so that soil samples will be collected for further evaluation. The analytical process is as per the accepted business and worldwide standards. Based mostly on the evaluation, a site investigation report is prepared containing the precise geotechnical information together with the necessary recommendations.

The soil testing providers offered by a properly reputed engineering consultancy will assist in determining the overall quality of the land. Within the building business this includes area testing of soil and rocks. Normally, the exams embody plate bearing tests and in site density testing, crucial for getting correct geotechnical data. Soil and rock testing entails tests for ascertaining the efficacy of level load, frost heave, direct Our Blog Here shear power, magnesium sulphate, etc. Likewise, one has to determine the slake sturdiness index alongside and on the similar additionally ascertain the present density and water content material levels. Equally, additional assessments must be carried out for analyzing the density and particle size, soil suction and moisture content. Assessments using the BRE and TRI strategies are conducted to establish the mandatory data.

Soil testing services are essential for determining the suitability and the general soil quality of a constructing mission. Conducting the required assessments will throw up essential geotechnical information that may assist in figuring out whether or not the soil characteristics and high quality is appropriate causes of soil degradation for the structure or not. It is vitally necessary to have this information beforehand as it helps in taking informed decisions and also enable you to plan strategically. Further, the data produced by these tests will tell whether the soil suitability complies with the business and national standards.

Engineers, planners and consultants in the development trade are required to supply an expert report for any development activity in the bushfire susceptible areas. The primary aim of the bushfire report is to guard lives and properties from any bushfire threats. A comprehensive report helps in growing a sound strategy to restrict the damage to lives and properties.

Measuring and controlling soil moisture is important to rising and sustaining healthy plants. To a novice, many of the phrases regarding soil moisture will be complicated. Living Soil Trailer On this primer we try and define and relate the various technical phrases related to soil moisture, and to describe cutting-edge soil moisture sensors.

One of the best ways to think about soil is to use the analogy of a sponge. When you dip a dry sponge into water it will take in water slowly till it's completely saturated. Once you pull it out of the water, water will gush out shortly, because of the effect of gravity, and after a couple of minutes the water will drip out of it at an increasingly slower fee until it stops dripping. The point at which the sponge is filled with water, yet gravity can not pull water out of it's analogous to the measurement we name discipline capability. When the soil has been saturated, and any excess water has been removed by gravity, the soil is at subject capacity. That is also referred to water holding capability (WHC).

Now suppose you are taking a vacuum cleaner and place its hose on the sponge. If powerful enough, the suction of the vacuum cleaner will pull water out of the sponge, until most of the water is eliminated. Observe that no matter how robust the vacuum is, a bit little bit of water will remain within the sponge, and it'll appear moist. To drive out all the water from the sponge, you would need to warmth it. We compare this to soil where the vacuum represents the roots of a plant. The roots suck water out of the soil with a stress decided by capillary motion. https://www.youtube.com/watch?v=fd467Li6HUw&t=22s The plant will have the ability to suck extra water out of the soil until the capillary strain can now not overcome the soil's stress to retain the water. This level at which a plant's root can not extract water is named the "keen point", which as you can imagine is a critical parameter.

One more essential term is the "plant out there water". This is the out there amount of water in soil that may truly be used by the plant. Just because soil may have water in it does not imply that the plant has sufficient "suck" to pull it out. So the definition of plant accessible water is the holding capacity minus the wilting point. Good soils have giant plant available water, which means they have excessive holding capability, and low wilting factors, so that water is offered, and straightforward for the plant to extract.

As soil varies in composition, so do these parameters. Soil types are outlined by their particle measurement. Sand is coarse - in fact, and clay is made up of very fine particles, whereas silt is a medium particle size. As a result of clay soil has very effective particles it tends to hold moisture properly, but it surely also holds on to it so the wiling level of clay is sort of excessive, making it tough for crops to extract the moisture. Sandy soil could be very porous and so water flows out easily, and a consequence it has low holding capability. The right soil has high holding capability, and a low wilting point. To realize this good soil, soils of different particle dimension are combined along with organic matter equivalent to humus.

Now that we have now mentioned how soil holds water, we will focus on easy methods to measure soil moisture. Because the objective of measuring soil moisture is to know if plants are getting sufficient water, we'd wish to measure the water that is accessible to their roots. Ideally we'd measure the water with an "synthetic" root. One very correct method of doing this is with a tensiometer, which measures the water as a operate of stress. Since it measures pressure or tension its items are additionally by way of pressure. The tensiometer does not tell you what the absolute moisture content of the soil is, but hearkening back to our soil moisture analogy, tells you the way a lot strain it takes to suck water out of the soil.

Many technical articles describe results from tensiometers and give items in pressure corresponding to bars, etc. Now when you occur to know what kind of soil the tensiometer is measuring, then you'll be able to compute absolutely the soil moisture or not less than get an estimate of it. A clay soil might have high moisture content, and on the identical time have a high pressure, rendering the moisture ineffective to the plant. While tensiometers are correct, and provide helpful information they're delicate and costly scientific devices that require specialised knowledge to operate and interpret. They're also slow within the sense that they've to come into equilibrium with the surrounding soil earlier than a measurement can be made, so they are not excellent to be used in making fast measurements.

Another comparable strategy to the tensiometer is the gypsum block. This is primarily 2 stainless steel electrodes which might be encased in plaster. As moisture absorbs into the gypsum resistivity decreases. The gypsum serves as a salt barrier. Many low-cost soil moisture sensors include two chrome steel rods that insert into the soil. This strategy is highly inaccurate resulting from salts within the soil which might wildly change the resistance of the soil, and thus give inaccurate readings of moisture content material.

The gypsum block sensor partially overcomes salinity issues with the gypsum barrier. The principle disadvantages with gypsum blocks is that they're sometimes slow and bulky. After a block is positioned within the soil, there is a lag before the gypsum involves the same moisture stage as the encircling soil. As a result of they're large and obtrusive they cannot be utilized in potted plants. The output of a gypsum block is an electrical resistance, this is in turn associated to moisture within the units of strain with using search for tables.

Modern soil moisture sensors use electronics to measure the dielectric fixed of the encompassing material which happens to be associated to moisture content. These sensors are also called capacitive soil moisture sensors, or TDR soil moisture sensors. These sensors are small and unobtrusive so they can be used with potted vegetation, provide immediate readings, are simple to make use of, are very inexpensive, and plenty of are low power. Due to their low value and low power necessities, these types of sensors are being massively deployed in irrigation methods in wireless mesh networks equivalent to Zig bee networks.

These sorts of electronic probes measure the soil moisture in absolute phrases, namely the amount of water to the quantity of soil, additionally know as VWC. One other associated soil moisture measurement unit is GWC or gravimetric water content material, which is defined as the mass of water, to the mass of soil. VWC and GWC are related by the majority density of the soil, so if you already know the density of the soil you may convert from one to the opposite. VWC is more generally used. VWC can be related to pressure, to transform from one to the other the type of soil have to be known. As was mentioned, a clay soil may have a excessive VWC, however a plant could have a hard time extracting water from it.

Accurate measurement and interpretation of soil moisture data, can allow people or computerized techniques make decisions about water utilization, saving precious water assets, and promoting healthy vegetation.

[jobskenyaplace]

TENDER FOR PROPOSED DRILLING AND EQUIPPING OF A BOREHOLE AND OTHER WATER WORKS

COUNTY GOVERNMENT OF TANA RIVER TENDERS OCTOBER 2024  DEPARTMENT OF CLIMATE CHANGE TENDER NOTICE The County Government of Tana river invites interested firms to undertake the following tenders. NO TENDER NO DESCRIPTION BID BOND (Ksh) RESERVATIONS 1 TRCG/OT/CCCF/ 001/2024-2025 Proposed Drilling and Equipping of Take Cluster Borehole in Hirimani Ward, Tana North Sub-County, Tana River…

[juniperpublishers-ttsr]

Special Design of Heavy Mass Base Foundations Methods in Rocks and Clay Soil Sub-Surfaces Techniques

Abstract

These paper constitute consists of parts of foundations design of under and sub structural plans. First of all, foundations are the lowest artificially prepared parts of the structures which are in direct contact with ground surfaces are known as Foundations. But its different categories for the zones of ground ability. Most of the foundations are normal status and load distribution neutralizations in normal bearing values of depends upon the soils. But rocks and clay soil zones areas not suited for normal sub structural design methods. Its followed by high precious design sections and execute the better results. And followed design methods is used for high precious focus in mountain and steep constructions, Water-bearing area, it's also better suitable in heavy constructions mass base foundation methods of high rise buildings system.

Keywords:   Rock boring; Grout hole; Anchorage bolting systems; Mass base trapezoidal foundations designs

    Introduction

The soil ground on which the foundation's rest is that foundation bed or foundation soil and it ultimate bearing of loads and interact with the foundations of structure [1]. Case study and objective of foundations to distribute the total load coming on the structure on a large area as well as great supported on the structure and required enough stability of the structures against various disturbing forces such eradicated climatic barriers. And to prepare the level of surfaces for concreting and masonry work. Inspections of sites its desirable to recognize the site of works and inspect them carefully from the viewpoints of foundation details [2]. And to analyse the nature and thickness of strata of soil may be estimated by studying the excavation detail of nearby constructionor by examining the open side of a nearby well etc. the general inspection of site of works serves of a good guide for determining the type of foundation to be adopted for the proposed work and in addition, it helps in getting the data with respects to used for design purposes. That following data is used for items. The behaviour of ground due to variation in depth of water table, Capacity of percolation of storm water at the site, nature of the soil and visual analyzation, movement of ground due to any reason [3]. Examinations of grounds, The load of the structure is ultimately transferred to the soil it becomes, therefore, essential to know the quality and thickness of soil undergrounds and such as a study would assist in selecting an economical but safe design for the foundation of the structure [4].

    Methods

That Figure 1& 2 represents the special form of trapezoidal foundation mass basements and deep grout anchorage systems. Its, essentially high interlock grip effect with substructures to superstructures. Its typically handled in 50mm deep boreholes and required depth essentially carrying out of deep boring for big important engineering structure [5]. Its methods anchor bolts rock concrete grout such as the addition to the of the ability of superstructure, importance is to be given to various other factors such as the same application in dams. Boring is followed by the 2-methods, Percussions boring machines and core rotary equipment.

In this process, the heavy cutting tool is dropped into the ground by means of a series of blows. That method used to prefer in a semi layer hard rock soil and rock layer zones areas. The broken rock material is brought to the ground by adding water into the core and then the paste is lifted to the ground. The material thus obtained is made dry and it is then examined. The percolations of boring machines is very much use of hard rock zones areas [6], And another condition it is very old method better results values and created a large number of vibrations in heavy blowing. Some problems cracking in nearest structures.

Core and rotary drilling machines

In this process, a hollow tube is driven by rotary motion which cuts a solid core. Water is used to facilitate the cutting process [7], That machines can be used either for soft or hard rocks materials. If the tube passes through a hard material, the core is retained and this has to be cut at the bottom and lifted up [8], This is done by pouring sand at the inner side between the core and inner surface of the tube and then the tube is slightly rotated [9], The core is then broken and caught in the tube along with sand and it is lifted up.

Anchorage bolts and concrete systems assembly

After the 25 to 50mm boreholes and provided the bolting anchorage rods used in the rock in required foundations depths [10], And its mostly used in peikko anchorage systems in better in rock foundation methods. At one head of fixed bolt head into the provided in required depth of rock. And after pouring the settling concrete. And setting properly and to tighten the top of the bolting rod. Its better frictions joints of the basement and foundations to substructures levels [10]. Referred the design approach of followed in ASTM, A36, A307 (Grade B), A325, A449 and A687 [11]. Used in concrete. The Bolt threads at the surrounded closing stages of apiece threaded steel bar are stake at top and bottom places below the grave curse nut. That concrete is placed in well-hardened status in 14- days after to tightening to bolt rotation.

Rock grouting

Boreholes in sufficient number are driven in the ground. The concrete grout is then forced under pressure through these bore holes [12]. These any of crack fissures of the rock are thus filled up, resulting in the increased of bearing power of rock. Its process aided to some other chemical treatment certain chemicals are used in place of cement grout to solidify the but this process is adopted by small-scale construction is costly it is only in case of important building.

Figure 3 & 4 Represents the Mass Trapezoidal basement foundations on clay and clayey soils. Clay and clayey soil is a partial work in cohesive and cohesive less in seasonal climatic conditions [13]. It is highly preferred in irrigations systems and not preferred in shallow foundations. That foundation is broadly shallow spread over the construction site area. Its possibly to constructed foundations are termed trapezoidal basement foundation. In such spread case of overall in a raft. And to assemble the assembly structural column sections. Its high economical evaluation in compared to other pile foundations better load transparent in cohesive soils.

Design criteria of special mass basement footing

The total load to be transmitted by the walls or columns to the foundation beds. The results of foundation pits and the corresponding bearing capacity of each stratum of soil [14]. It respects to 2 aspects.

Width of foundations

A width of the special footing basement is decided by adopting the following rules:

If no footing is to be provided to the constructional site area, it will provide the assumption columns should be provided in required depth and equal areas as shown in Figure 1. The total load including dead load and wind load coming on the columns per meter length at are in case of heavy construction the load aspects in the centre of the basement, it worked out. Then the width of the foundation is obtained from the following relation.

a. For column,

The width of foundation basement = {Total load per meter length /allowable bearing capacity of the soil}

b. For piers,

The width of foundations basement = {Total load on the pier/allowable bearing capacity of the soil}

Usually, the wall, columns, piers are given with of basements connects to plinth level. By adding the width of offset of concrete, the total width of foundation can be obtained. And this width of increased bearing pressure is vice versa to increase Table 1.

Depth of foundations

As a general rule, all the heavy mass base foundation should be taken to a minimum depth of 80 cm below natural ground level unless the hard soil is available within 80 cm. the total load is transferred to the soil per square meter can be worked out and after the study of the results of the trial pits, the foundation should be taken to such a depth at which the soil has an allowable bearing capacity greater than the value. The depth of foundations can also be obtained by drawing the lines of angles 450 and 600 as shown in Table 2. Rafting methods are increased the bearing power of soil becomes very useful when the load coming on the soil is practically uniform while soil yielding nature.

    Conclusion

It is a final conclusion of the paper is special mass base heavy foundation technique is followed by critical soil and Rock category suitable preferred of the important structure. Such structure has to be designed for heavy loads and ordinary methods of providing foundations may not be suitable for structure. In that such case, methods handling in special heavy basement footings is resisted to heavy loads and increased the bearing capacity pressure of soil. That concept of a method of increasing the bearing power of clayey soil becomes useful, especially when there is used in a ground floor structure.

To Know More About Trends in Technical and Scientific Research Please click on: https://juniperpublishers.com/ttsr/index.php

For more Open Access Journals in Juniper Publishers please click on: https://juniperpublishers.com/index.php

For more about Juniper Publishers Please click on: https://www.zoominfo.com/c/juniper-publishers-inc/370428819

[helmerichpayne]

NONLINEAR DYNAMICS OF A DRILLSTRING IMMERSED IN A 3D CURVED WELL, SIMULATIONS AND EXPERIMENTS

During drilling operations, the bit-rock and drillstring-wellbore contacts with stick-slip phenomena, fluid structure interaction, and mass unbalances distributed along the drillstring yield nonlinear dynamics coupling axial, torsional, and lateral vibrations. Excessive and uncontrolled vibrations may induce drilling equipment damage due to fatigue, cracking, and ruptures.

Understanding and predicting the drilling dynamics become necessary to avoid those harmful vibrations. The drillstring dynamics is modelled in the time domain using the beam finite element method. The contact between the drillsting and borehole is accounted for using radial elastic stops and the fluid effect on the drillstring dynamics is considered by two models. The initial position is obtained from a static equilibrium computation that takes into account the drillstring pre-load.

The dynamics is then calculated by applying a time-integration scheme. The dynamic model is applied to a real case of a quasi-vertical well with field measurements of downhole vibrations along with surface data. Numerical simulations are carried on a drilling assembly of several kilometers' length.

The novelty of the proposed dynamics model is its ability to consider a realistic geometry of drilling assembly in 3D curved wells with fluid flows, and to give a complete study of the coupling phenomena between axial, torsional, and lateral vibrations. Read out the full tech paper here: https://www.helmerichpayne.com/resources/technical-publications/nonlinear-dynamics-of-a-drillstring-immersed-in-a-3d-curved-well-simulations-and-experiments or you can also contact us here: https://www.helmerichpayne.com/contact.

[renewablenergy2021]

Geothermal Energy utilization in Indian context

Geothermal Energy utilization in Indian context

Geothermal Energy Introduction

Power plants convert the heat to electricity. Geothermal energy as the name suggests it is the heat energy from the earth that is being utilized for electricity generation or direct heating and cooling processes. This energy comes from the original formation of planet Earth & from the radioactive decay of materials. It is contained in the rocks and fluids beneath the earth’s crust and can be found deep at the earth’s hot molten rock called magma.

The difference in temperature between core of the planet (Approx.  4000 °C) & its surface, termed as Geothermal gradient which drives the conduction of the heat energy from the core to the surface of the planet earth. This high temperature and pressure in the earth’s interior causes some rock to melt and solid mantle to behave plastically and convecting upwards being lighter than surrounding rock. 

A global perspective on Geothermal energy

To limit global temperature, rise to 1.5°C and bring CO2 emissions closer to net-zero by 2050, clean and sustainable energy technologies are to be prominently used. Geothermal has been a clean, environmentally friendly, sustainable, and expanding source of energy in recent years. These are usually located close to tectonically active regions in the earth’s crust. According to the International Renewable Energy Agency (IRENA), geothermal energy has grown steadily from around 10 GW globally in 2010 to 14 GW in 2020. The total installed capacity for geothermal direct heat utilization for heating/ cooling (excluding heat pumps) is around 23 GWth.

The first geothermally generated power was produced in Larderello in Italy in 1904. The world geothermal map as indicated in figure 2 shows that the United States is the largest producer of geothermal energy in the world followed by Indonesia.

During the 21st Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC), held in Paris, France, in December 2015, the Global Geothermal Alliance (GGA) was formed of which India is a member, to increase the use of geothermal energy, both in power generation and direct use of heat. India has set a target of installing 175 GW of renewable energy by 2022 majorly by solar and wind energy. Geothermal energy in India is still at a nascent stage given site-specific nature, risk, and uncertainties with exploration and high capital cost

India’s Perspective on Geothermal Energy

A ‘hot springs committee’ consisting of the National geophysical research institute (NGRI), Geological Survey of India, and Jadavpur University, Kolkata was formed in 1963 by the ministry of power and irrigation to explore the utilization of thermal springs in India commercially. In 1971, India sought assistance from the United Nations in preparation for the report on the geothermal resource development project, and the final project document was updated in 1973. After, 1973, the Geological Survey of India (GSI) with CSIR – National Geophysical Research Institute (NGRI) carried out a preliminary resource assessment for the exploration and utilization of geothermal resources.

There are about 300 thermal spring localities in India as per the Geological Survey of India (GSI) report 2002 and these localities were grouped into geothermal provinces having estimated potential to produce around 11 GW. Chief geothermal provinces in India are shown in figure 3 which includes the Himalayas, Naga-Lushai province, Sohana, West coast, Andaman-Nicobar Islands, Cambay, Son-Narmada-Tapi (SONATA), Godavari, and Mahanadi valleys.

In 2007, MOU between the Centre of Excellence for Geothermal energy (CEGE, Ahmedabad) India and Iceland geo survey (ISOR) Iceland took place for cooperation on geothermal development in India.

In 2015 MNRE launched a draft national policy on geothermal energy to establish India as a global leader in geothermal power by installing 1GW in the initial phase by 2022. After the Paris summit on climate change, India proposes to install 10 GW geothermal energy by 2030 through active international collaboration with the US, Philippines, Mexico, and New Zealand.

On 7Th Feb 2021, the Agreement for establishing India’s first-ever geothermal field development project was signed, a step towards the goal of carbon-neutral Ladakh and MOU was signed between union territory administration of Ladakh, Ladakh Autonomous hill development council (LAHDC), and Oil & Natural gas cooperation (ONGC) energy center. This project will put India on the geothermal power map of the world. Puga and Chhumathang in eastern Ladakh is the most promising geothermal field in India as per the GSI where the deepest borehole was drilled up to 385 m depth and 220 m depth respectively.

These geothermal provisions are classified as medium enthalpy (100 to 200 Deg C) and low enthalpy (less than 100 Deg C) geothermal systems depending on the temperature profiles. Puga and Chummathang in Ladakh and Tatapani in Chhattisgarh are medium enthalpy geothermal systems that can be used for power production. The utilization of geothermal energy depends on the quantity and quality of the fluid and its temperature and pressure.  In Puga, Ladakh geothermal fluids are used for extraction and refinement of borax and sulfur along with experimental space heating for a long time through shallow wells drilled.

Recently, ONGC has planned Puga field development geothermal project in Ladakh in three phases. Phase-I involves exploratory-cum-production drilling of wells up to 500 metres depth and setting up of a Pilot Plant of up to 1 MW power capacity. Phase-II would involve deeper and lateral exploration of geothermal reservoir by drilling of optimal number of wells and setting up of a higher capacity Demo Plant and preparing a Detailed Project Report. Phase-III would involve commercial development of the geothermal plant.

Application routes of geothermal energy

The low-temperature heat energy from the earth crust can be utilized directly through direct heating and cooling of buildings, drying processes and industrial process heating applications whereas the high-temperature heat energy of about 150 Deg C can be used to generate the uninterrupted electricity.

Direct Exploitation

·        Provide heat for building.

·        Hot springs as Spa.

·        Heating water at fish farms.

·        Provide heat to industrial processes.

·        Raising plants in greenhouses, drying crops.

Indirect Exploitation

·        Electricity generation & heat recovery

Hot water or steam deep below the earth surface at high temperature are drilled out to obtain environmental friendly, continuous, carbon-free, uninterrupted clean energy in the geothermal power plants by the use of turbines, generators, and transformers as being done in conventional power plants.

Geothermal electric power generations can be classified into three types as shown in figure 6. Dry steam plants are the oldest form of geothermal technology and take the steam out of the ground through production well and use it to directly drive a turbine. It is used when high-temperature steam is available. Transportation, storage, and combustion of the fuel are eliminated leading to the least land footprint among various energy generation technologies. Flash steam plants use high-pressure hot water into cool, low-pressure water. Hot water flows up through the well in the ground under its own pressure. As it flows upwards, pressure is reduced and hot water boils into steam. Steam is separated from water in the flash tank and is further utilized to generate power. Separated water and condensed steam are injected back to the reservoir for reheating through an injection well. Binary cycle plants pass hot water through a heat exchanger where secondary liquid with a lower boiling point (organic compound), turns to vapor and is used to drive the turbine.

Also Read: Geothermal Energy Scope in India

References:

1.    https://www.energy.gov/eere/geothermal/

2.    https://www.power-technology.com/features/what-is-geothermal-energy/

3.    http://www.globalgeothermalalliance.org/

4.    https://www.ongcindia.com/wps/wcm/connect/en/media/press-release/geothermal-energy-ladakh

5.    Geothermal energy provinces in India: A renewable heritage by Kriti Yadav & Anirbid Sircar https://www.sciencedirect.com/science/article/pii/S2577444120300617

6.    http://164.100.94.214/geothermal-database-india

7.    https://www.gsi.gov.in/webcenter/portal/OCBIS/pagePublications

.      https://www.renewable-india.com/geothermal-energy-utilization-in-indian-context/

[annieboltonworld]

Juniper Publishers-Open Access Journal of Environmental Sciences & Natural Resources

Level of Toxicity of Leachate from the Mpasa Technical Landfill Site in Kinshasa, Democratic Republic of Congo (DR. Congo)

Authored by K Wanduma

Abstract

The leachate (the water that has percolated through the waste stored in a landfill by biologically and chemically loading…) from the Mpasa landfill leaves a noticeable imprint in the wall of the container that contains it. A landfill that produces leachate has multiple environmental consequences such as soil toxicity, subsoils, groundwater and streams. The present study evaluates the degree of toxicity of the percolate of this Mpasa landfill. The samples were taken in one campaign using a canoe in the 250-liter plastic drums. In this study, a pilot consisting of colored plastic cups containing various levels of aqueous solutions of juice (percolate) from Mpasa site of 10-5 to 100 ml/ml as well as Gambusia affinis fish were considered bioindicators. Previous physico-chemical analyzes show high values of the parameters studied. It is the pH (12.3); Electrical Conductivity (EC) (7700 μS / cm); the concentration of oxygen (O2) (1360 μg /l); the suspended solids concentration (MES) (462,000 μg / l) and the chemical oxygen demand (COD) (13,797,000 μgO2/l). After 4 days on average dissolution, the study shows that the lethal concentration that removes half of all survivors reaches a volume of 0.006 ml of leachate / ml of solution. This confirms a severe toxicity. The ecotoxicology tests on leachates show a 10% change in LD50 that ranges from 10-4 ml / ml to 10-3 ml / ml.

Keywords:Leachate; Toxicity; Landfill; Gambusia Affinis; Mpasa; Kinshasa; DR Congo

Introduction

The amount of municipal waste is increasing in both controlled and uncontrolled landfills in cities and urban areas [1]. The cities of the Democratic Republic of Congo, especially the capital Kinshasa does not escape this rule. It develops intense nuisances with real and bad consequences on the inhabitants. These environments are therefore in full demographic growth supported by anarchic urbanization, by the rural exodus, by mass migrations of populations in search of the best conditions of life. These situations do not favor the development of socio-economic, ecological and environmental factors [2]. In these cities, if less effort is being made to manage solid wastes, there are rarely any bad water pipes, retention ponds and sewage treatment plants and/or even less complex liquids treatment such as leachates. In a biodegradable waste storage center, the bins are built for the containment and compacting of waste. While the drains serve to route the percolation water that seeps through the decaying waste mass and pipes lead the gas to the flare.

Aerobic and anaerobic biological processes under these climatic conditions produce percolation water commonly known as leachate [3,4]. However, according to Kmet quoted by Khattabi, 20% of precipitation leads to leachate production [5,6]. While Stegmann cited by the same author found different percentages depending on the state of compaction of the waste, 15 to 25% of the rain form leachate for compacted landfills and 25 to 50% in the case of an uncompacted discharge [7].

The city of Kinshasa province was endowed since May 2010 with its only storage center (final discharge) of municipal solid waste without prior treatment under the aegis of the European Union [8]. The European Union had built the first bin in May 2010 and the 29th, the last to be built dates from the year 2015. The rains fall 9 months on 12 months in annual average on the site Mpasa, swept by a humid tropical climate. They have a great influence on the technical exploitation of the site, the sizing of traps and retention ponds and the production of leachates [9,10] (Table 1).

The lagoon ponds constructed at Mpasa have shown their purifying limit against the fouling character, the mineral and organic composition of these discharge juices [11-13]. These retention ponds can only be used as a storage place in search of a suitable and more efficient treatment method of the intensive activated sludge type, using bio-coagulants and bio-flocculants to be purified before any discharge into the wild.

Since the climate of this zone allows the production of a high flow of leachates up to 250.10-6 m3 per second in the rainy season, they are loaded with organic matter and mineral matter, which flow through the massifs of waste. These contain less biodegradable organic matter than refractories and minerals, giving them complex and toxic characteristics [14]. The nature of physical, chemical, biological constituents and the quality of the liquids circulating in this waste storage center can be the subject of intensive research in ecotoxicology. This research is useful for assessing the toxicity of polluted effluents from a medium, microorganisms, dissolved or suspended organic substances and organic substances [15,16]. It has been proven that Mpasa’s raw leachates are toxic and difficult to biologically treat [17]. The objective of this research is to determine the toxic chemical, ecotoxicological and microbiological components of landfill leachate from Mpasa to Kinshasa (DR Congo) in relation to conventional release standards, as shown in Figure 1. We have conceived in this research.

Materials and Methods

Geomorphology and Environment

The relief of Kinshasa consists of a plateau (Bateke) to the east, a chain of hills to the south and west and a plain to the north dotted with marshy areas in the neighborhoods of the Congo River. The Bateke Plateau is located between 600 and 700 m above sea level and completely dominates the south-eastern part of the city [18]. The Mpasa site is located in the Mpasa 3 district, N’selé commune, 5 km from Lumumba Boulevard, which is withdrawing to the town hall (Figure 2) [19].

The urban area of Kinshasa extends over 9,965 km2, or 0.42% of the area of the Democratic Republic of Congo [20]. It is located in the west between 3.9 and 5.1 degrees south latitude and between 15.2 and 16.6 degrees east longitude. The current population of Kinshasa is estimated at about 12,000. 000 inhabitants with a population growth rate of more than 4.7% per year (INS, 2014).

Soil Permeability

The penetration tests of water injected at depth as a function of infiltration time were monitored using a piezometric probe in four boreholes drilled using an auger, a chronometer and the water to be injected. These tests show that the permeability is greater in the soil used, as shown by the results in Table 1 of this research than in the control, the off-site and out-of-trap area.

Sampling

A leachate sampling campaign was held in April 2014 and constituted the sample grid. This period is devoted to violent storms from the end of February to April to produce an abundant flow of Mpasa discharge juice with a flow rate of 250 x 10-6 m3 / second (Figures 3-5). Physico-chemical analyzes were performed using plasma-mediated plasma spectrometry (ICP-MS) and X-ray fluorescence (Spectro XEPOS AMETEK). The acute toxicity method was used for ecotoxicological testing. The HACH HQ40d Multi-Parameter and the HACH 2400 Series Spectrophotometer were used to collect the dissolved oxygen concentration and to assay the major elements of the leachate.

Biological Materials

Leachate Collection: Leachate samples were collected using canoe, boots and gloves in the lagoon ponds of the Mpasa landfill. They were kept in 7 barrels of 250 Liters and transported to the garden JEEP (Garden and livestock plots) of the University of Kinshasa (Figures 3-5).

technique consists in preparing 500 ml artificial rearing ponds, a series of decimal dilutions of which 100 (100 ml of leachates or the mother concentration), 10-1 (10 ml of leachates + 90 ml of dechlorinated water) , 10-2 (10 ml concentration 10-1 + 90 ml dechlorinated water), 10-3 (10 ml concentration 10-2 + 90 ml dechlorinated water), 10-4 (10 ml concentration 10-3 + 90 ml of dechlorinated water), 10-5 (10 ml of the concentration 10-4 + 90 ml of dechlorinated water), and the control concentration (100 ml of dechlorinated water). Each pond was a lodge of 3 Gambusia affinis taken at 5 replicates equivalent to 15 individuals per concentration. The samples were analyzed according to the procedure proposed by Unkittrick and Mac Carty in 1995, concerning investigations and tests in environmental toxicology.

Methods of Analysis of Leachates

Briefly, the physico-chemical analyzes of this research, 5 ml of fruit juice, 0.7 ml of 65% HNO3 and 0.1 ml of 30% H2O2 were put in a Teflon bomb and digested overnight at 100 °C. The mixture was filtered through a 0.45 μm cellulose nitrate membrane and then diluted to 1/200 before assaying with ICP-MS according to the method of Mavakala et al. [23].

Microbiological Analyzes of Leachates

The sedimentation concentration technique (Ritchie method) consists of assembling and dissolving the residues after filtration of the leachates in ether, xylene and formaldehyde. The parasites are dragged to the bottom of the tube by concentration. The observation of parasitic worm eggs, larvae and cysts was read on fresh Motic microscope examinations and on the colored preparations according to the method of Gillet et al. [24].

Results and Discussion

The hot and humid tropical climate of Kinshasa is the abundant outcome of infiltration water indicating the difference in permeability in the soil of natural environments than in the one that has already undergone a reversal. The higher rainfall during nine months of rainy season favors the inflow of water percolating through the massive buried waste appearing in the (Tables 2-7). Toxicology tests on leachate from the Mpasa dump were carried out using bioindicators (Gambusia affinis) which is a species of fish adapted to in vitro biological tests. Their sensitivity to water quality is a conclusive indication of a highly polluted environment or not. The test consists in diluting the effluents to low concentrations to determine the lethal concentration 50 (Table 8).

OD= Dissolved Oxygen

TS : dissolved solids, TSS : suspended solid content. VSS : suspended solids volatiles FSS : Solids in suspension non flying.

The evaluation of the toxicity of the leachates produced at the Mpasa final discharge and tested in the laboratory for the level of toxic exposure level (LD50 of 0.006 ml / ml). The result of ecotoxicological tests in a population of 3 individuals of Gambusia affinis per pond reveals that within thirty minutes of breeding, all are killed at the concentration of 100 or 100% of deaths observed, then 77% of deaths the second day of concentration 10-1, then 33.3% of deaths in concentrations 10-2 and 10-3 on the third day. Exposure of this same population to the control at concentrations of 10-4 and 10-5 gave the result of 100% survivors until the last day of rearing.

Conclusion

This work being multi-disciplinary informs us that the leachates preserved more than twelve months from 12/04/2016 to 19/12/2017 continue to remain toxic for the populations of Gambusia affinis in its concentrations of 100, ie 0% of survivors observed, followed by the 10-1 dilution with 33% survivors, 66.7% in the 10-2, 10-3, and 100% dilution of the survivors in the 10-4, 10-5, and in the Witness solution. The range of concentrations 10-2 and 10-3 are close to the theoretical threshold of the LC50. The lethal dose of leachates is 0.006 ml / ml. The results of the physicochemical analyzes exceed the recommended normal thresholds (Pb (87.22 μg /l), Ar (7.07 μg /l) and Fe (3.3080 μg /l). The older the leachate, the more its constituents sediment. while retaining its toxic character [24] The toxic character of Mpasa leachates comes from the complex mixtures of domestic garbage collected in a set of industrial waste and household waste, without pre-treatment at source and which correspond to absolutely different lifestyles The hot and humid tropical climate of Kinshasa is the culmination of the abundance of seepage water indicating permeability ranging from 00 ‘to 07’ and from 00 ‘to 12’ in both environments in the first trap built by PARAU, the infiltration is from 00 ‘to 37’, while it is from 00 ‘to 24’ in the last trap, the more abundant rainfall during nine months of rainy season. ie favor the inflow of water percolating through the buried waste. This character is also the expression of the manner of burying the waste predisposed to the increase of the internal temperature which kills the parasites (0 Helminths, 0 Metazoans and 0 protozoa), but which selects the bacteria. Anaerobiosis conditions are established under the impetus of methanogenic bacteria causing numerous interactions between water and waste in the middle of which the polluting loads are carried to the retention pond. Finally, the sequence of fermentation and waste degradation processes, biochemical and chemical reactions, and the alternative of the aerobic and anaerobic biological states of the waste from the decomposing landfill contribute to the high toxic load leachates [22-24].

To know more about Juniper Publishers please click on: https://juniperpublishers.com/manuscript-guidelines.php

For more articles in Open Access Journal of Environmental Sciences & Natural Resources please click on: https://juniperpublishers.com/ijesnr/index.php

[juniperpublishers-imst]

An Analytical Model for Axial Force Transfer and the Maximum Compression Point of Work Strings in Extend Reach Drilling

Abstract

Complex work string dynamics are often observed when one is investigating the limit of Extended Reach Drilling (ERD), yet the underlying physical causes of anomalous problems are often not fully understood and is thus a topic of ongoing research interest. Theoretical models capturing tubular dynamics have been previously proposed to analyze force transfer in work strings, yet there is significant confusion regarding these models because their published versions are not entirely consistent and, in many cases, do not meet engineering requirement. Further confusion is introduced through variations in pin-pointing locations where axial compression in the work strings should be checked for mechanical integrity. A simple and yet rigorous mathematical model is essential for adequate prediction of axial compression profiles in work strings for ERD. This article presents a simplified tubular mechanics model for describing axial force transfer under ERD conditions. We discuss the model in finding the point of peak compression in casing strings. This point is predicted to be in the arc section near the heel of a horizontal wellbore, under borehole drilling, and casing running conditions. The exact location of the peak axial compression changes with pipe-wall friction coefficient. For the friction coefficient in the range of 0.15 to 0.35, this point occurs in the range of inclination angle between 70.7o and 81.5o, averaging 76.1o. The model can also be used for other purposes, including prediction of depth limit, bottom hole assembly (BHA) design, and locking up analysis of coiled tubing (CT) strings.

Keywords: Extended-reach-wells; Casing design, Work strings; Drilling; Stability

Introduction

Extended reach wells (ERW) are horizontal wells used for reaching oil and gas resources located laterally and far from well location. ERW has become a common practice over the last two decades for improving field economics. Extended Reach Drilling (ERD) is a technique to drill directional/horizontal wells beyond the routine capabilities of drilling rigs and tools. ERD was initiated in 1980’s and rapidly evolved during the 1990’s [1-4]. Naegel et al. [5] reported an ERD well with a 20,341.2 ft horizontal departure at 5,577 ft true vertical depth (TVD). ERD continued in the past two decades with new record updated every a few years [6-11]. Armstrong and Evans [12] reported planning and execution of an offshore ERD well of a total measured depth (MD) of 37,165 ft with TVD of 6,938 ft, and horizontal displacement (HD) of 33,682 ft. Tskhadaya et al. [13] presented a design of ERD for an Arctic well depth of 49,212.6 ft and horizontal borehole depth of 4,921.3 ft.

Special technical issues in ERD include rig requirement, borehole stability, cuttings transport, data acquisition, and drill string design. In the particular topic of our ongoing research interest, i.e., tubular mechanics of work strings (drill string, coiled tubing string, and casing string), Nixon et al. [14] presented techniques to solve the problems associated with excessive torque during ERD. Hill et al. [15] discussed designing and qualifying drill strings for ERD while Mason and Judzis [16] discussed the limit of ERD, and Suggett and Smith [17] addressed the issue of ERD limit for rig capacity. Bell et al. [18] reported an application of significant increases in the lateral reach of a number of ERW’s. Samuel [19] presented a new well-path design that can extend the reach of ERW through reducing torque and drag using curvature and torsion discontinuities. Agbaji [20] presented an algorithm that would set forth design for drilling programs suitable to ERD. Vestavik et al. [21] presented a potential application of Reelwell Drilling Method (RDM) to widen the envelope of ERD through reductions of torque and drag and Equivalent Circulating Density (ECD) gradient, and optimization of hydraulic weight on bit. Newman et al. [22] explained that for ERD with coiled tubing (CT) where a limitation on the horizontal displacement occurs due to frictional forces, the friction can cause helical buckling and lead to lockup of the CT strings, thus limiting reach. Gupta et al. [23] discussed several key challenges in ERD, including high torque and drag due to high friction forces.

Theoretical models capturing tubular dynamics have been previously proposed to analyze force transfer in the work strings used in ERD, yet there is significant confusion regarding these models because they are are not entirely consistent and, are hard to use due to model complexity. Also, no model has been found to have the capacity of pin-pointing the locations where the axial compression in work strings should be checked for mechanical integrity. A simple and rigorous analytical solution in closed form is presented in this work for adequate prediction of axial compression profiles in the work strings for ERD. We discuss the model in finding the point of peak compression in casing strings. This point is predicted to occur in the arc section, near the heel of a horizontal wellbore, under borehole drilling and casing running conditions. The model can also be used for other purposes, including prediction of depth limit, BHA design, and lockup condition analysis of CT strings.

Mathematical Model

Figure 1 illustrates a simplified configuration of a work string (drill string, casing string, or coiled tubing string) used in horizontal well construction engineering. Two-dimensional well trajectory of build-and-hold type is considered. The string is assumed to contact the lower side of borehole due to gravity in the curve and slant/horizontal sections without buckling. Owing to its large length-to-diameter ratio, the string is considered to be ropelike without stiffness. It is subjected to axial tension/compression but not bending moment.

The axial compression force in the vertical section of string increases with depth due to gravity. Its value at the kick-of-point (KOP) is expressed as

Where F0 is the axial compressive force in the string at KOP, wv is the weight per length of the string in the vertical section, V is the length of vertical string section, and T is the tension at the surface (hook load). In the down-ward motion, the axial compression force in the horizontal section increases with the distance from the end of string (toe of horizontal well) due to friction. The axial compression force at the heel reaches to

Where 2fθ is the axial compressive force in the string at the heel of horizontal well, μ is the friction coefficient between the string and borehole wall, wh is the weight per length of the string in the slant/horizontal section, H is the length of string in the slant/horizontal section, θ2 is the inclination angle at the heel point, WB is the force acting back by the borehole bottom (weight on bit in drilling condition), Ah is the cross-sectional area of string in the horizontal section, and pf is the fluid pressure in the bottom hole. If the slant section is truly horizontal (θ2 = π/2), Eq. (2) degenerates to

where Fπ /2 is the axial compressive force at the heel.

Because the axial compression force in the string is a continuous function of length, its value is expected to reach a maximum between F0 and Fπ /2 in the curved section. The axial compression force in the curve section is expressed as (see Appendix A for derivation):

Where wc is the weight per length in the curved section, and R is the radius of curvature.

Equation (5) is plotted in Figure 2 for Fπ/2 = 20,000 lb, wc = 17 lb/ft, and R = 1,000 ft for friction coefficient values ranging from 0.15 to 0.40. It indicates that a maximum value of axial compression exists near the heel, depending on friction coefficient.

The maximum axial compression force occurs at a point where the function is stationary. The derivative of this function is

Model Applications

This mathematical model can be used in casing design, drill string design, and coiled tubing stability analysis in horizontal well engineering. Two examples are illustrated in this section.

Casing Design. Casing strings for horizontal wells are designed considering multiple stress components that cause:

a) Burst failure due to net bust pressure

b) Collapse failure due to net collapse pressure

c) Tensile/compressive failure due to axial forces (gravity, friction, and bending)

The axial compression force can reduce the casing’s burst resistance performance. Suppose a 5½” J-55, 17 lb/ft, production casing is selected to run in the curve section of the borehole shown in Figure 3. The mud weight is 12.5ppg and friction coefficient is 0.30. It is required to check the reduced burst pressure resistance of the casing due to axial compression.

The API burst pressure resistance of the casing is [24]:

Where t is the thickness, dn is the nominal pipe diameter, and σyield is the yield stress

Radius of curvature is [24]:

Axial compression at heel is

A complete profile of axial force was calculated with the mathematical model and is shown in Figure 4. It shows a maximum axial compression near, but not at the heel.

The maximum axial compression is

The maximum axial stress due to weight and friction is

Bending stress is

Where σb is the bending stress, and E is the Young’s modulus of elasticity. The total axial compression is

API tangential stress factor for burst is [24]:

Where σt is the tangential stress.

Reduced burst pressure resistance of the casing is [24]:

which means that the axial compression will reduce burst pressure resistance of the casing from 5,320 psi to 4,699 psi, or by 12%.

Drill String Design. Drill strings for horizontal wells consists of drill collar design, considering friction forces in the curved and horizontal sections, under drilling conditions (down-ward motion), and drill pipe design considering over-pull under, tripping-out conditions (upward motion).

Consider the situation shown in Figure 5. Design parameters are given in Table 1. Equation (2) gives

The required drill collar weight is (1.15)(28,415) or 32,677 lb. Based on the unit weight of 92 lb/ft of the drill collar, the required drill collar length is (32,677)/(92) or 356 ft.

For drill pipe design, the curved linear length of the arc section is (800)(80)/(57.3) or 1,117 ft. The weight of the lower drill pipe is (16.25)(3,000+1,117) or 66,900 lb. Based on the tensile capacity of Grade G steel pipe, 436,000 lb, the maximum pull on the Grade G drill pipe with design factor is (436,000)/(1.15) or 379,130 lb. The maximum permissible weight of Grade G pipe string with over pull of 100,000 lb is

379,130 – 66,900 – 32,677 – 100,000 = 179,553 lb The maximum permissible length of this pipe string is (179,553)/(19.5) or 9,208 ft, which is greater than the needed length of 10,000 – 3,000 – 1,117 – 356 = 5,527 ft,

Conclusion

An analytical model for axial force transfer and the maximum compression point in work strings for ERD was developed in this investigation. The following conclusions are drawn.

a) The maximum axial compression point is in the arc section near the heel of a horizontal well when the work string is in down-ward motion. The exact location of the maximum axial compression changes with casing-wall friction coefficient. For μ = 0.15 ~ 0.35 in horizontal well engineering, the maximum axial compression occurs with θ = 70.7o ~ 81.5o, averaging 76.1o.

b) When applied to casing design, the maximum compression point model can be easily used to evaluate the reduction of the casing’s burst resistance performance. Results show that the casing’s burst resistance performance can be significantly reduced due to axial compression (12% in the illustrative example).

c) When applied to drill string design, the axial force transfer model can be easily utilized to determine the required drill collar weight and length, which is further used for selecting drill pipe string.

d) Future studies should validate the mathematical model and investigate the applicability of the model to CT stability analysis and predict the depth limit of ERD.

To Know More About Insights in Mining Science & Technology Please click on: https://juniperpublishers.com/imst/index.php

For more Open Access Journals in Juniper Publishers please click on: https://juniperpublishers.com/index.php

For more about Juniper Publishers Please click on: https://www.zoominfo.com/c/juniper-publishers-inc/370428819

[augerbit]

The lifted drill pipe columns are sequentially discharged in the derrick

Due to the wear and erosion of the teeth, the bearing damage of the cone bit will cause the cone to rotate inflexibly or the cone to jam.After a roller cone bit has been working for a period of time, the diameter of the bit's blade will become smaller, shorter, and blunt at the same time, which will directly affect the ability to crush rocks. 

Therefore, in order to speed up the drilling speed, the drill bit must be replaced in time. The purpose is to keep the liquid level in the wellbore from dropping, so that the wellbore The pressure can balance the formation pressure to prevent the wellbore from collapsing or the fluid in the downhole formation enters the wellbore. 

The lifted drill pipe columns are sequentially discharged in the derrick. The workers will unload the old drill bit and install the new drill bit and go down into the well according to the original column sequence to resume drilling.. Drilling workers use the crane, traveling block and hook on the derrick to pull out all the drilling tools from the well according to the height of the derrick. 

After all the drill pipes and drill collars in the wellbore are lifted out, the drill bit that needs to be replaced will come out at the same time. While the downhole drill string is proposed, the drilling pump should be used to continuously inject the drilling fluid into the annular space. 

At the same time, special attention should be paid to the sticking that may custom Standard brad point wood bits Factory occur due to the shrinkage of the borehole wall, and the operator must strictly control the lifting speed

[jobskenyaplace]

VARIOUS TENDER NOTICE LAIKIPIA UNIVERSITY SEPTEMBER 2024  

LAIKIPIA UNIVERSITY TENDER SEPTEMBER 2024  OFFICE OF THE VICE CHANCELLOR TENDER NOTICE                          Laikipia University invites interested eligible suppliers to apply for the following tenders: TENDER NO. TENDER DESCRIPTION ELIGIBILITY TENDER/ BID SECURITY PRE-TENDER LU/TEN/01/2024/25 Proposed drilling and installation of Solar-Powered Borehole Water Pump OPEN KES. 20,000 1st…